Sealing element for pavement grooves



A ril 20, 1965 A. F. CRONE 3,179,026

SEALING ELEMENT FOR PAVEMENT GROOVES Filed June 5, 1964 I NVENTOR Alfred Ir" Crone ATTORNEY6' V Patented Apr. 26, 1955 3,179,026 SEALING ELEMENT FOR PAVEMENT GROOVES Alfred F. Crone, 385 N. Forest Road, Williamsvilie, NY. Filed June 5, 1964, Ser. No. 373,000 8 Claims. ((31. 94-18) This application is a continuation-in-part of my copending application Serial No. 107,842 filed May 4, 1961 and now abandoned.

This invention relates to a seal for use in joints in pavements and other structures, and particularly to a preformed seal or article which is inserted in a construction or pavement joint to provide a seal therefor.

It is necessary that joints be used in pavement or other structures to allow for expansion and contraction of a given length of structure under varying temperature conditions, and due to shrinkage of the material while hardening. Such joints are slots or grooves between adjacent lengths of pavement which are wide enough to accommodate the lineal expansion of the pavement under warm weather conditions. The joints are usually formed by a spacer member which is inserted between adjacent pavement strips when they are laid down, or by subsequently sawing a groove in a continuous strip of pavement before it has permanently set.

Such grooves or joints are formed in pavements or other structures, such as dams, tanks and the like. My improvements will be herein described mainly in connection with pavements, but it will be understood that the. same improvements may equally well be employed in other structures.

These grooves are provided in connection with expansion joints which are formed crosswise of a pavement or highway for compensating for expansion of longitudinally extending pavement sections, or in connection with contraction joints also between such longitudinally extending pavement sections which compensate mainly for the contraction of the pavement sections in which the compression strength of the paving material is relied upon to prevent damage to the pavement due to expansion of the pavement sections. In both of these types of joints an important function is to prevent irregular breaking of the pavement due to expansion or contraction of the pavement since such irregular breaks are difiicult to repair. The grooves for expansion and contraction joints serve mainly the purpose of providing lines of weakness extending crosswise of the pavement to cause any stresses in the paving material tending to break the pavement to do so along straight lines extending crosswise of the pavement. Such breaks in the pavement can be more readily repaired.

Pavement grooves or joints are also formed between longitudinal strips of pavement, for example, of a two lane highway, to receive seals which prevent foreign material from entering the joints or grooves between these adjacent longitudinal strips or lanes of pavement. The sealing elements herein described may be used in connection with any of these joints.

These grooves must be sealed in order to prevent accumulation of unwanted particles such as sand or gravel, and to prevent infiltration of water, which in cold weather would lead to heaving and cracking of the pavement adjacent the joint. It has been standard practice for many years to fill such grooves with an asphalt or similar type of filler which would yield during warm weather when the width of the joint becomes smaller due to expansion of the adjacent pavement lengths. Joints having such filling materials must be repaired and replaced periodically and normally require inspection and repairs at six month intervals.

To solve this problem compressible sealing strips which can be inserted within the joints have been proposed.

Examples of such devices are strips of solid materials such as sponge rubber, or of natural rubber units having an exterior ridged wall and a hollow interior section.

These articles have not solved the problem satisfactorily, primarily because it was not possible to keep a good seal. The units had poor wear characteristics, insuiiicient expansion capability, low abrasion resistance, and deteriorated when subjected to temperature extremes, sunlight, weathering, and oxidation. These units consequently lost resilience and were incapable of expanding and contracting with changes in width of the joint. As a result, these articles did not come into widespread use as a sealer for pavement joints.

The specific disadvantage of asphalt and similar type of sealing compounds lies in failure to adhere to the side walls of the joint or in cracking during cold weather therby creating fissures which permit water, gravel and other foreign particules to enter the joint, and to ultimately damage the joint and adjacent pavement. This condition also tends to result in the extrusion of the sealing material from the joint during warm weather, since the sand and. other foreign material entrained within fissures of the seal when the joint is at maximum width during cold weather will act to extrude the sealing material out of the joint when its width becomes a minimum in warm weather. As a result of these limitations in the conventional sealing material, it is necessary to periodically inspect and repair such joints.

Accordingly, it is the general object of this invention to overcome the drawbacks of the prior seal devices and sealing materials.

It is a further object of this invention to provide a sealing strip which has a long life and is practically permanent in nature, requiring little or no maintenance after installation.

It is a still further object of this invention to provide a preformed pavement sealing strip which will have a long life and will not deteriorate when subjected to varying weather conditions in a pavement joint.

It is also an object of this invention to provide a preformed sealing strip which is easily inserted within a joint, and which will readily compress to approximately one-half of its original width.

A still further object of this invention is to provide a sealing strip which has side walls that are continuously forced outwardly and into engagement with the side walls of the joint under all weather conditions.

It is a still further object of this invention to provide a sealing strip for joints which has thin walls and an internal truss structure which exerts a strong outward pressure against the side walls of the sealing strip to keep them in forced, continual engagement with the side walls of the joint.

Other objects and advantages of my invention reside in the details of construction, arrangement, combination of the various parts of my apparatus as hereinafter more fully set forth, as specifically pointed out in my claims, and illustrated in the accompanying drawing, in which:

FIG. 1 shows in cross section the sealing strip and the joint with the sealing strip shown prior to compression and just before insertion within the joint.

PEG. 2 is a similar cross sectional view showing the sealing strip after insertion within the joint.

FIG. 3 is a similar cross sectional view also showing on a slightly larger scale than FIG. 1 the same scaling strip joint at the maximum width of the joint for extreme cold weather conditions.

FIG. 4 shows in perspective a wedge-shaped sealing strip similar to that shown in FIGS. 1 to 3 which has outwardly flared side walls for wedge-shaped grooves in pavement.

FIG. 5 shows a section of pavement illustrating the use of the sealing strip in both transverse and longitudinal pavement grooves.

Referring particularly to the drawings, FIG. 1 shows in cross section the sealing strip S in its uncompressed state immediately prior to insertion in a joint and between two adjacent pavement slabs generally indicated at P. The sealing strip is an elongated, extruded or molded member made of an elastomeric material having thin side walls 12 andl iwhich meet downwardly inclined top walls 16 and 18 at a pointed apex and 19 respectively. Bottom walls 2i and-22 are downwardly inclined and meet at an apex 26 to facilitate insertion of the sealing strip between the adjacent faces 5% and 52 which form the joint between the adjacent pavement sections P.

It will be noted that the ribbing within the exterior walls of the seal encloses two diamond-shaped sections 24 and 3 which allow compression of the ribbing without interference, as can be seen from FIG. 2, which shows the compressed sealing strip after it has been inserted into the expansion joint.

The ability to compress the sealing strip to approxi mately one-half of its uncompressed width while retaining a strong outward pressure against the adjacent side walls of the joint is an important feature of this unit. The use of an internal ribbed truss of thin section to support the thin outer walls of the sealing strip has been found to be extremely effective means of accomplishing both of these results.

The diagonal ribs 3-2 and 34 assist in supporting the central portion of walls 12 and 14 respectively by connecting them with the central, interior portion of the top walls 16 and 18 immediately below the central groove 17. These ribs thus become one member of a triangular truss section including the rib, the top wall, and the upper portion of the side wall of the sealing strip.

Diagonal ribs 36 and 38 similarly support the sealing strip side walls, and with diagonal ribs 32 and 34 form the central, interior, diamond-shaped cavity 30. Diagonal ribs 36 and 38 are joined at their apex to upwardly extending diagonal ribs 40 and 42, the latter being connected at the juncture of the sealing strip side and bottom walls.

It is to be noted that ribs 36and 40 form a structural triangle with the lower section of side wall 12, and that diagonal rib members 38 and 42 form a structural support triangle with the lower sections of wall 14, and that each of these triangular configurations meet at an apex to give mutual support to each other. It will be noted that pressure exerted at the central section of, side wall 12 is resisted along a line of force through member 36 and then through member 42 which is integral with the opposite side wall 14. v V

The arrangement of these diagonal support ribs is such that they are rigidly fastened in an internal truss arrangement which is extremely rigid and strong and yet takes up very little space. At full compression the unit is not hindered by interference fronrunnecessarily overlapped support ribs or from excessively thick sections.

In this regard, it should be noted that the top walls 16 and 18, and the bottom walls and 22 as well as the side walls 12 and 14 serve as structural support members in the truss configuration. Bottom walls 2% and 22 also assist in guiding the strip into position during the initial phase of insertion into the joint. Upper walls 16 and 18 because of their downward orientation, and because of their additional thickness'will, when compressed, force the central grooved section 17 downward, thereby minimizing the tendency of the top walls 16 and 18 to bulge upwardly. An upward bulge of the top walls to a point where they are above the level of the pavement will contribute to failure of the seal from impact with traffic.

FIG. 2 shows in cross section the seal immediately after insertion and shows the manner in which the seal collapses into the diamond-shaped areas 24 and 30, as well as the fiexure of the diagonalrib members. Both FIGS.

2 and 3 are on a slightly larger scale than that shown in FIG. 1, to more plainly illustrate the action of the ribs in the internal truss arrangement of this device. FIG. 3 illustrates the seal strip in cross section under cold weather conditions Where the groove has a maximum width, and clearly shows that there is some compression and buckling of the support ribs for this condition too.

The sealing strip S must be under compression at all times to insure successful sealing action, and due to the considerable dimentional change in the width of the joint, it is essential that the compression strip be capable of being reduced to approximately one-half of its uncompressed Width;

FIG. 4 shows in perspective the end portion of a transverse groove seal member S having similarly identified parts of the sealing strip S shown in FIGS. 1. through 3. Sealing strip S is used for transverse or longitudinal grooves on concrete pavement strips. FIG. 5. shows a section of pavement wherein a sealing strip .84) is used in a transverse joint. This would correspond to the sealing strip S shown in FIG. 4. For a concrete pavement having adjacent pavement strips sixty feet in length, a concrete groove of inch width, and two inch depth is required. The width of the treihsverse sealing strip S for such a groove is of an inch between apexes 15' and 19 with a total height 1 and inches. The depth of the grooves is the distance from the top surface of the pavement P down to the step '58 as shown in FIGS. 2 and 3.

The groove shown in these figures is a typical construction which can be made by using molding pieces, or by sawing the partially hardened concrete before it has finally set.

FIG. 5 shows the transverse sealing strip extending across two pavement strips in position with an end section 82 which is bent to extend down along the edge of the groove to seal the end thereof. A separate longitudinal strip is shown in a groove which has been sawed lengthwise of the pavement and through the transverse strip 80 to separate the pavement into two lanes.

It is absolutely essential that the material from which the sealing strip is made be extremely flexible and that it does not deteriorate or lose its resilience after exposure to the elements. This has been the drawback of previous devices, and applicant has found that it is essential to use a low crystallization type elastomeric compound to assure successful operation of the sealing strip. An ordinary rubber material will not meet the necessary requirements since it will lose its resilience due to the effect of ozone, sunlight and temperature variance. The low crystallization elastomeric which applicant has found to be successful after considerable testing has been neoprene synthetic rubber, and this has made it possible for the sealing strip to work effectively with no maintenance over a period of more than three years. It is absolutely necessary that the sealing strip retain its resilience and not take a permanent set so that it may expand and contract as the width of the joint changes under varying temperature conditions. This characteristic of resilience makes it possible for the seals to be installed and maintenance thereof dispensed with.

The resilience of the sealing strips and their ability to be compressed will assure a tight seal between the faces of the groove and the sealing strip walls. In addition to this quality, it is necessary that the material have good wear resistance to abrasive materials such as sand and gravel, and that it have good resistance to petroleum products and chlorides as well as general weather conditions. Neoprene has good resistance to these deteriorating agents also.

The sealing strip S is inserted in the joint'by hand using a roller which presses down on the top wall sections 16 and 18. Before inserting such strip however, it is essential that the joint be cleaned, and that a layer of lubricantadhesive be applied to the joint walls 50 and 52. Such a layer is shown at 54 and 56 ofF IGS. 1 2 and 3 This material is a liquid neoprene glue suspension. The sealing strip S is applied before the suspension has a chance to dry so that the liquid will reduce friction between the sealing strip and the walls of the joint. The films 54 and 56 of lubricant-adhesive seal the pores in the pavement immediately adjacent the sealing strip,- and also adhere the Walls of the sealing strip to the pavement Walls 50 and 52. When the sealing strip is in position, its topmost portion should be approximately of an inch below the pavement surface. i

As pointed out earlier, it is important that the entire ribbing of the structure be sufficiently strong to maintain constant pressure against the side walls of the joint. However, it is also essential that the ribbing be thin in section and that a minimum reinforcing be used so that the sealing strip width can be compressed as much as possible to accommodate changes in the width of the seal joint.

While the invention has been described, it will be understood that it is capable of further modifications and this application is intended to cover any variations, uses, or adaptations of the invention following in general the principles of the invention and including such departures from the present disclosure as come within known or customary practice in the art to which the invention pertains, and as may be applied to the essential features hereinbefore set forth and as fall within the scope of the invention or the limits of the appended claims.

I claim: 1

1. A sealing strip for joints comprising:

(a) an elongated hollow body of low crystallization elastomeric material having two thin side walls, a top wall, and a bottom wall;

(b) each of said side walls being substantially flat, equal in length, and substantially longer than said bottom and top walls;

(0) said hollow body having an internal truss structure connected to said side walls so that a strong support is provided thereby to oppose lateral deformation of said walls; and j (d) said truss structure having diagonal rib members which are interconnected and have spaces therebe tween which will permit said rib members to collapse into said spaces when said side walls are laterally compressed; and

(e) said rib members forming a plurality of connected triangular sections, one of the members of each of said triangular sections being a portion of said side walls.

2. The sealing strip for joints as set forth in claim 1 wherein said top wall comprises two downwardly inclined straight wall sections which meet and are joined at their lower ends to form a central apex, said sections each being thicker than said rib members, and at their upper ends meeting and joining their corresponding side walls to form a point, so that said straight wall sections will deflect downwardly with minimum upward bulge when said side walls are compressed laterally.

3. The sealing strip for joints as set forth in claim 1 wherein said bottom wall comprises two downwardly inclined wall sections which meet and are joined at their lower ends to form a central apex, and are connected at their upper ends to their respective side walls, so that the sealing strip can more readily be fitted into a joint.

4. The sealing strip for joints as set forth in claim 1, wherein said material is neoprene synthetic rubber.

5. A sealing strip for joints comprising:

(a) an elongated hollow thin-walled body of low crystallization elastomeric material having side walls, a bottom wall, and a top wall,

(b) a pair of diagonal support ribs disposed within said body and which converge and join at their upper end With a central point of said top wall, each of said ribs at their lower ends being integral with one of said side walls adjacent the center portion thereof;

(0) a second pair of diagonal support ribs disposed Within said body which cross and are integral with each other at approximately their mid-point, and are each integral at their upper end with the central portion of one of said walls, and each such diagonal support rib being integral at its lower end with the other 10 of said side walls adjacent the lower end thereof; and

(d) said crossed diagonal support members each making an angle of at least 30 degrees with said walls.

6. The sealing strip for joints as set forth in claim 5 wherein said top wall comprises two downwardly inclined straight wall sections which meet and are joined at their lower ends at a central apex, each of said straight wall sections being thicker than said diagonal support ribs, and at their upper ends meeting their corresponding side wall at a point so that said straight wall sections will deflect downwardly with minimum upward bulge when said side walls are compressed.

7. The sealing strip as set forth in claim 5 wherein said bottom wall comprises two downwardly inclined sections which meet and are joined at their lower ends at a central apex and are connected at their upper ends to their respective side walls, so that the sealing strip is more readily fitted into a joint.

8. A sealing strip for joints comprising:

(a) an elongated hollow thin-walled body of low crystallization elastomeric material having side walls, a bottom wall and a top wall, said side walls being substantially flat;

(b) a pair of diagonal support ribs disposed within said body and which converge and are joined at their upper end with a central point of said top wall, each of said ribs attheir lower ends being integral with one of said side walls adjacent the center portion thereof;

(c) a second pair of diagonal support ribs disposed within said body which cross and are integral with each other at approximately their mid-point, and are each integral at their upper end with the central 7 portion of one of said side walls, and each such diagonal support rib being integral at its lower end with the other of said side walls adjacent the lower end thereof;

(d) said crossed diagonal support members each making an angle of at least 30 degrees with said walls;

(e) said top wall comprising two downwardly inclined straight wall sections which meet and are joined at their lower ends at a central apex, said sections each being thicker than said diagonal support members, and at their upper ends meeting their corresponding side wall to form a point so that said straight wall sections will deflect downwardly with minimum up ward bulge when said side walls are compressed; and

(7) said bottom wall comprising two inclined sections which meet and are joined at their lower ends and are connected at their upper ends to their respective side Walls, so that the sealing strip is more readily fitted into a joint.

References Cited by the Examiner JACOB L. NACKENOFF, Primary Examiner, 

1. A SEALING STRIP FOR JOINTS COMPRISING: (A) AN ELONGATED HOLLOW BODY OF LOW CRYSTALLIZATION ELASTOMERIC MATERIAL HAVING TWO THIN SIDE WALLS, A TOP WALL, AND A BOTTOM WALL; (B) EACH OF SAID SIDE WALL BEING SUBSTANTIALLY FLAT, EQUAL IN LENGTH, AND SUBSTANTIALLY LONGER THAN SAID BOTTOM AND TOP WALLS; (C) SAID HOLLOW BODY HAVING AN INTERNAL TRUSS STRUCTURE CONNECTED TO SAID SIDE WALLS SO THAT A STRONG SUPPORT IS PROVIDED THEREBY TO OPPOSE LATERAL DEFORMATION OF SAID WALLS; AND (D) SAID TRUSS STRUCTURE HAVING DIAGONAL RIB MEMBERS WHICH ARE INTERCONNECTED AND HAVE SPACES THEREBETWEEN WHICH WILL PERMIT SAID RIB MEMBERS TO COLLAPSE INTO SAID SPACES WHEN SAID SIDE WALLS ARE LATERALLY COMPRESSED; AND (E) SAID RIB MEMBERS FORMING A PLURALITY OF CONNECTED TRIANGULAR SECTIONS, ONE OF THE MEMBERS OF EACH OF SAID TRIANGULAR SECTIONS BEING A PORTION OF SAID SIDE WALLS. 